Database applications let users interact with information that is stored in databases. Databases provide structure for the information, and allow it to be shared among different applications.
Delphi provides support for relational database applications. Relational databases organize information into tables, which contain rows (records) and columns (fields). These tables can be manipulated by simple operations known as the relational calculus.
When designing a database application, you must understand how the data is structured. Based on that structure, you can then design a user interface to display data to the user and allow the user to enter new information or modify existing data.
數(shù)據(jù)庫應(yīng)用程序的開發(fā)可以幫助用戶直接訪問到數(shù)據(jù)庫中的信息，這些信息通常被設(shè)計(jì)成某種特定的結(jié)構(gòu)存放在數(shù)據(jù)庫中，以便讓不同的應(yīng)用程序訪問。
Delphi支持關(guān)系型數(shù)據(jù)庫的應(yīng)用程序，關(guān)系型數(shù)據(jù)庫一般由一個(gè)或多個(gè)數(shù)據(jù)表組成，數(shù)據(jù)表包括行（紀(jì)錄）和列（字段）。我們可以對數(shù)據(jù)表執(zhí)行一些簡單的操作命令。這就是通常所說的關(guān)系型結(jié)構(gòu)。
設(shè)計(jì)一個(gè)數(shù)據(jù)庫應(yīng)用程序，首先確定為應(yīng)用程序建立一個(gè)什么樣的數(shù)據(jù)庫，然后設(shè)計(jì)用戶界面，建立應(yīng)用程序與數(shù)據(jù)庫之間的聯(lián)系，實(shí)現(xiàn)更新數(shù)據(jù)和輸入數(shù)據(jù)的操作。
下面介紹一下在設(shè)計(jì)數(shù)據(jù)庫應(yīng)用程序過程中的一些常見問題：
數(shù)據(jù)庫的應(yīng)用
數(shù)據(jù)庫的結(jié)構(gòu)
設(shè)計(jì)用戶界面